“Unfortunately, he suffered a torn ACL in his left knee and will most likely miss the 2014 season,” general manager Doug Whaley confirmed in a statement released by the team. “He will be scheduled for surgery in the near future and begin a rehabilitation program at the appropriate time. We feel badly for Kiko because he has worked very hard this offseason in preparation for the upcoming season, but we look forward to his return with his style of play that made him one of the league’s outstanding rookies in 2013.”

Alonso was a second round pick out of Oregon, 46th overall. By the end of the year, he was second in Defensive Rookie of the Year votes behind New York Jets’ defensive end, Sheldon Richardson.

“I was pleased with how I did, but when I watch film, I see that I left a lot of plays out there,” he said.

That would make room for free agent signee Brandon Spikes. Instead, Alonso’s 159 tackles, four interceptions and two sacks are now out of play for the Bills. Syracuse.com lays out some of the options the Bills might explore to replace Alonso.

Alonso had hip surgery in May and was gearing up for training camp by working out in Oregon, where he has a home.